Self-prioritization in working memory gating

Working memory (WM) involves a dynamic interplay between temporary maintenance and updating of goal-relevant information. The balance between maintenance and updating is regulated by an input-gating mechanism that determines which information should enter WM (gate opening) and which should be kept out (gate closing). We investigated whether updating and gate opening/closing are differentially sensitive to the kind of information to be encoded and maintained in WM. Specifically, since the social salience of a stimulus is known to affect cognitive performance, we investigated if self-relevant information differentially impacts maintenance, updating, or gate opening/closing. Participants first learned to associate two neutral shapes with two social labels (i.e., "you" vs. "stranger"), respectively. Subsequently they performed the reference-back paradigm, a well-established WM task that disentangles WM updating, gate opening, and gate closing. Crucially, the shapes previously associated with the self or a stranger served as target stimuli in the reference-back task. We replicated the typical finding of a repetition benefit when consecutive trials require opening the gate to WM. In Study 1 (N = 45) this advantage disappeared when self-associated stimuli were recently gated into WM and immediately needed to be replaced by stranger-associated stimuli. However, this was not replicated in a larger sample (Study 2; N = 90), where a repetition benefit always occurred on consecutive gate-opening trials. Overall, our results do not provide evidence that the self-relevance of stimuli modulates component processes of WM. We discuss possible reasons for this null finding, including the importance of continuous reinstatement and task-relevance of the shape-label associations.

Object coding in peripersonal space depends on object ownership

Previous studies have shown that objects located in the peripersonal space (PPS) receive enhanced attention, as compared with extrapersonal space (EPS), However, most objects in the environment belong to someone in particular and how object ownership influences object coding in relation to PPS representation is still unclear. In the present study, after having chosen their own mug, participants performed a reachability judgement task of self-owned and other-owned mugs presented at different distances while facing a virtual character. This task was followed, on each trial, by a localisation task in which participants had to indicate where the mug, removed from view, was previously located. The two tasks were separated by a 900-ms visual mask during which the virtual character was unnoticeably shifted by 3° to evaluate the spatial frame-of-reference used. The results showed that self-owned mugs were processed faster than other-owned mugs, but only when located in the PPS. Furthermore, reachability judgements were biased for self-owned mugs, leading to an extension of the PPS representation, especially for participants with a high score on the fantasy scale of Interpersonal Reactivity Index (IRI). Finally, the virtual character shift altered the localisation performance but only for the distant mugs, suggesting a progressive shift from egocentric to allocentric frame-of-reference when moving from the PPS to EPS, irrespective of object ownership. Overall, our data reveal that the representations of ownership and PPS interact to facilitate the processing of manipulable objects, to an extent that depends on individual sensitivity to the social presence of others.

Affective compatibility with the self modulates the self-prioritisation effect

The "self" shapes the way in which we process the world around us. It makes sense then, that self-related information is reliably prioritised over non self-related information in cognition. How might other factors such as self-compatibility shape the way self-relevant information is prioritised? The present work asks whether affective consistency between the self and arbitrarily self-associated stimuli influences the degree to which self-prioritisation can be observed. To this end, participants were asked to associate themselves with either a positive or a negative concept and to then indicate if a given stimulus (Experiment 1: Emotional faces; Experiment 2: Luminance cues) and an identity label matched. If affective consistency is key to self-prioritisation, negative constructs should dampen self-prioritisation and positive constructs should boost self-prioritisation because the self is universally construed as positive. Indeed, the results of the two experiments indicate that participants who made the negative association had more difficulty confirming whether the stimulus and the label matched than those who made the positive association. The implications of this finding are discussed in terms of "self" theories that span various levels of information processing. The data reveal that self-referential information processing goes beyond a default elevation of priority to the self.

Sticking together? Re-binding previous other-associated stimuli interferes with self-verification but not partner-verification

The self-prioritisation and we-prioritisation effects can be observed through faster responses to self-stimuli (self and group) than non-self-stimuli. It remains uncertain if we-prioritisation extends to individual members of one's own group. In light of recent work that implicates memory-based processes in identity-prioritisation effects, the present experiment was developed to determine whether a task-partner's identity relevant information also benefits from an enhanced representation, despite conflicting evidence of partner-prioritisation. To this end, pairs of participants were recruited to perform a joint task. Each partner was assigned a shape and a stranger was also assigned a shape. Participants then completed a shape-to-label matching task where one participant responded if a shape and a label pair matched and the other responded if the shape and a label pair did not match. Halfway through the task the associated identities were switched such that the same shapes and labels were reassigned. Overall, a standard self-prioritisation effect was observed with match-responders making faster responses to self- over partner- and stranger-stimuli. After identities were remapped a decrement in performance was observed for self-trials relative to baseline self-responses. Conversely, responses were faster to partner- and stranger-stimuli relative to baseline performance for each stimulus type. Thus, no evidence was observed for an enhanced representation for task-partner-associated identities. However, an interaction between old and new memory traces for self- and other-associated identities does seem to interfere with self-retrieval and self-verification processes.

Stranger to my face: Top-down and bottom-up effects underlying prioritization of images of one's face

Recent studies suggest that we rapidly and effortlessly associate neutral information with the self, leading to subsequent prioritization of this information in perception. However, the exact underlying processes behind these effects are not fully known. Here, we focus specifically on top-down and bottom-up processes involved in self-prioritization, and report results from three experiments involving face detection, using a sequential match-non-match task. Across the three experiments we asked participants to associate an unfamiliar face with the self (Experiment 1), to associate one's face with a stranger's name (Experiment 2), and to establish both associations simultaneously (Experiment 3). We found that while participants showed evidence of bottom-up prioritization of their real faces, they did not show such an effect for self-associated strangers' faces. However, the participants showed a robust self-related top-down effect; when presented with a self-related cue, they were later faster at classifying both subsequent correct and incorrect targets. Together, our results suggest that self-prioritization is underpinned by distinct top-down and bottom-up processes. We discuss our findings in the context of the proposal that the self acts as an "integrative glue", and suggest an interpretation of our results within the framework of predictive coding.

Valence and ownership: object desirability influences self-prioritization

Research has demonstrated that possession exerts a potent influence on stimulus processing, such that objects are categorized more rapidly when owned-by-self than when they belong to other people. Outstanding theoretical questions remain, however, regarding the extent of this self-prioritization effect. In particular, does ownership enhance the processing of objects regardless of their valence or is self-prioritization restricted to only desirable items? To address this issue, here we explored the speed with which participants categorized objects (i.e., desirable and undesirable posters) that ostensibly belonged to the self and a best friend. In addition, to identify the cognitive processes supporting task performance, data were submitted to a hierarchical drift-diffusion model (HDDM) analysis. The results revealed a self-prioritization effect (i.e., RT_self < RT_friend) for desirable posters that was underpinned by differences in the efficiency of stimulus processing. Specifically, decisional evidence was extracted more rapidly from self-owned posters when they were desirable than undesirable, an effect that was reversed for friend-owned posters. These findings advance understanding of when and how valence influences self-prioritization during decisional processing.

Self-prioritization of fully unfamiliar stimuli

Recently, Sui and colleagues introduced an experimental task to investigate prioritization of arbitrary stimuli associated with the self. They demonstrated that after being told to associate three identities (self, friend, stranger) with three arbitrary stimuli (geometrical shapes), participants were faster in a perceptual matching task to recognise matching pairs of self-associated shape with self-label, than respective friend or stranger-related pairings. They interpreted this as evidence that a brief self-association is sufficient to facilitate processing of previously neutral stimuli. However, in the matching trials of the self-prioritization task, participants are processing not only self-associated arbitrary stimuli but also familiar verbal labels with an established meaning. Therefore, the self-advantage may be caused by familiarity of the labels, rather than self-association of the shapes. To test whether self-prioritization can be elicited in a task employing exclusively neutral stimuli, we asked participants to associate avatar faces with three identities (self, name of best friend, and stranger) and replaced labels with unfamiliar abstract symbols that were associated to the words (you, friend, stranger) before the actual experiment started. The results presented the usual pattern of self-prioritization showing that this effect does not critically depend on the presence of familiar labels and that it can be elicited in the absence of any familiar stimuli.

Listening to yourself is special: Evidence from global speech rate tracking

Listeners are known to use adjacent contextual speech rate in processing temporally ambiguous speech sounds. For instance, an ambiguous vowel between short /α/ and long /a:/ in Dutch sounds relatively long (i.e., as /a:/) embedded in a fast precursor sentence, but short in a slow sentence. Besides the local speech rate, listeners also track talker-specific global speech rates. However, it is yet unclear whether other talkers’ global rates are encoded with reference to a listener’s self-produced rate. Three experiments addressed this question. In Experiment 1, one group of participants was instructed to speak fast, whereas another group had to speak slowly. The groups were compared on their perception of ambiguous /α/-/a:/ vowels embedded in neutral rate speech from another talker. In Experiment 2, the same participants listened to playback of their own speech and again evaluated target vowels in neutral rate speech. Neither of these experiments provided support for the involvement of self-produced speech in perception of another talker’s speech rate. Experiment 3 repeated Experiment 2 but with a new participant sample that was unfamiliar with the participants from Experiment 2. This experiment revealed fewer /a:/ responses in neutral speech in the group also listening to a fast rate, suggesting that neutral speech sounds slow in the presence of a fast talker and vice versa. Taken together, the findings show that self-produced speech is processed differently from speech produced by others. They carry implications for our understanding of rate-dependent speech perception in dialogue settings, suggesting that both perceptual and cognitive mechanisms are involved.

"I" and "Me": The Self in the Context of Consciousness

James (1890) distinguished two understandings of the self, the self as "Me" and the self as "I". This distinction has recently regained popularity in cognitive science, especially in the context of experimental studies on the underpinnings of the phenomenal self. The goal of this paper is to take a step back from cognitive science and attempt to precisely distinguish between "Me" and "I" in the context of consciousness. This distinction was originally based on the idea that the former ("Me") corresponds to the self as an object of experience (self as object), while the latter ("I") reflects the self as a subject of experience (self as subject). I will argue that in most of the cases (arguably all) this distinction maps onto the distinction between the phenomenal self (reflecting self-related content of consciousness) and the metaphysical self (representing the problem of subjectivity of all conscious experience), and as such these two issues should be investigated separately using fundamentally different methodologies. Moreover, by referring to Metzinger's (2018) theory of phenomenal self-models, I will argue that what is usually investigated as the phenomenal-"I" [following understanding of self-as-subject introduced by Wittgenstein (1958)] can be interpreted as object, rather than subject of experience, and as such can be understood as an element of the hierarchical structure of the phenomenal self-model. This understanding relates to recent predictive coding and free energy theories of the self and bodily self discussed in cognitive neuroscience and philosophy.

Social targets improve body-based and environment-based strategies during spatial navigation

Encoding the position of another person in space is vital for everyday life. Nevertheless, little is known about the specific navigational strategies associated with encoding the position of another person in the wider spatial environment. We asked two groups of participants to learn the location of a target (person or object) during active navigation, while optic flow information, a landmark, or both optic flow information and a landmark were available in a virtual environment. Whereas optic flow information is used for body-based encoding, such as the simulation of motor movements, landmarks are used to form an abstract, disembodied representation of the environment. During testing, we passively moved participants through virtual space, and compared their abilities to correctly decide whether the non-visible target was before or behind them. Using psychometric functions and the Bayes Theorem, we show that both groups assigned similar weights to body-based and environment-based cues in the condition, where both cue types were available. However, the group who was provided with a person as target showed generally reduced position errors compared to the group who was provided with an object as target. We replicated this effect in a second study with novel participants. This indicates a social advantage in spatial encoding, with facilitated processing of both body-based and environment-based cues during spatial navigation when the position of a person is encoded. This may underlie our critical ability to make accurate distance judgments during social interactions, for example, during fight or flight responses.

Prioritization of arbitrary faces associated to self: An EEG study

Behavioral and neuroimaging studies have demonstrated that people process preferentially self-related information such as an image of their own face. Furthermore, people rapidly incorporate stimuli into their self-representation even if these stimuli do not have an intrinsic relation to self. In the present study, we investigated the time course of the processes involved in preferential processing of self-related information. In two EEG experiments three unfamiliar faces were identified with verbal labels as either the participant, a friend, or a stranger. Afterwards, participants judged whether two stimuli presented in succession (ISI = 1500ms) matched. In experiment 1, faces were followed by verbal labels and in experiment 2, labels were followed by faces. Both experiments showed the same pattern of behavioral and electrophysiological results. If the first stimulus (face or label) was associated with self, reaction times were faster and the late frontal positivity following the first stimulus was more pronounced. The self-association of the second stimulus (label or face) did not affect response times. However, the central-parietal P3 following presentation of the second stimulus was more pronounced when the second stimulus was preceded by self-related first stimulus. These results indicate that even unfamiliar faces that are associated to self can activate a self-representation. Once the self-representation has been activated the processing of ensuing stimuli is facilitated, irrespective of whether they are associated with the self.